Final answer:
J.R.R. Tolkien, a British author, invented languages such as Quenya, Sindarin, and The Black Speech for his fantasy works including The Lord of the Rings and The Hobbit.
Step-by-step explanation:
The British author who invented languages such as Quenya, Sindarin, and The Black Speech was J.R.R. Tolkien. Tolkien, a renowned writer and linguist, created these languages as part of his fantasy works, including The Lord of the Rings and The Hobbit. Quenya and Sindarin are Elvish languages spoken by different groups of Elves in Middle-earth, while The Black Speech is the language used by the evil forces, such as Sauron and his servants.